Device for stabilizing catheters and method of use thereof

ABSTRACT

A device for stabilizing catheters such as delivery catheters is disclosed. The device includes a radially expandable structure which extends from a proximal end to an opposing distal end. The expandable structure is secured to a stabilizer catheter at its proximal end. The device includes means to position the delivery catheter relative to the expandable structure. The means may include one or more attachment members arranged to extend distally from the distal end of the expandable structure. Each attachment member is coupleable to a connector projecting near a distal tip of the delivery catheter. The means may alternatively include one or more sleeves, each arranged for the respective one of the delivery catheters to insert therethrough. A retractable catheter sheath is moveable along the longitudinal axis of the expandable structure to extend the expandable structure between a compressed configuration and an expanded configuration. A kit for stabilizing catheters is also enclosed. The kit includes a delivery catheter. The delivery catheter may comprise a connector projecting near a distal end thereof for coupling the attachment member. A method of use of the device for the delivery of biocompatible materials is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of PCT application No.PCT/CA2021/051790 filed 13 Dec. 2021, which claims priority from USapplication No. 63/127,471 filed 18 Dec. 2020 and entitled DEVICE FORSTABILIZING CATHETERS AND METHOD OF USE THEREOF which is herebyincorporated herein by reference for all purposes. For purposes of theUnited States of America, this application claims the benefit under 35U.S.C. § 119 of US application No. 63/127,471 filed 18 Dec. 2020 andentitled DEVICE FOR STABILIZING CATHETERS AND METHOD OF USE THEREOF.

FIELD OF THE INVENTION

The invention pertains to devices for stabilizing catheters, and methodsof using such devices for delivery of biocompatible materials into theheart of a subject.

BACKGROUND OF THE INVENTION

It is known in the art to use catheters for delivery of biocompatiblematerials into tissues of a subject. For example, it is known in thefield of cardiology to use anchor delivery catheters to deliverventricular anchors in the myocardium in the left ventricle of theheart. It is desirable for a device to stabilize delivery catheterswhich can provide for precise, controlled and/or atraumatic delivery ofbiocompatible materials into a specific implantation location in thesubject.

SUMMARY

One aspect of the invention provides a device for stabilizing catheters,such as delivery catheters. The device has a radially expandablestructure. The expandable structure has a proximal end extending to anopposing distal end. The distal end is defined by a distal edge. Thedistal edge may for example have a circular or elliptical shape. Thedevice includes means for positioning one or more delivery cathetersrelative to the expandable structure. In some embodiments, such meansincludes one or more attachment members arranged to extend distally froma point along the distal edge of the expandable structure. The one ormore attachment members are each coupleable to a respective one of aconnector projecting near the distal tips of one or more deliverycatheters for securing the delivery catheters to the expandablestructure. The distal tips may be positioned at a point equal to orgreater than a radial limit of the expandable structure. In otherembodiments, such means includes one or more sleeves extending from aproximal end to a distal end. One or both of the proximal end and thedistal end of the sleeves are secured to the expandable structure, suchas by welding. Each one of the delivery catheters is insertable througha respective one of the sleeves. Means are provided to extend theexpandable structure between the expanded and compressed configurations.The means may comprise a retractable catheter sheath. Selective movementof the retractable catheter sheath along a longitudinal axis of theexpandable structure extends the expandable structure between theexpanded and compressed configurations.

Another aspect of the invention provides a kit for stabilizingcatheters. The kit comprises the device for stabilizing catheters, andone or more delivery catheters. The one or more delivery catheters mayinclude a connector, each of which is arranged to couple to anattachment member. The connector may be arranged to project from asurface of the delivery catheter near a distal tip of the catheter.

Another aspect of the invention provides a method for using the deviceto deliver biocompatible materials to a body of a subject. In an exampleuse embodiment, the device is used to deliver ventricular anchors in themyocardium of the left ventricle of the heart. The method optionallyinvolves securing an expandable structure to a stabilizer catheterand/or one or more delivery catheters to form a device. The device isadvanced into the body within a region proximate to the desiredimplantation location. The expandable structure is radially expandedwithin the region. The method may first involve partially expanding theexpandable structure. The partially expanded expandable structure may berotated to position the respective distal tips of the one or moredelivery catheters at the desired implantation location. When the distaltips are precisely positioned, the expandable structure may then befully expanded. The fully expanded expandable structure contacts thesurfaces within the region in order to stabilize the delivery catheterfor controlled delivery of the biocompatible materials into the specificimplantation location. After delivery of the biocompatible materials,the expandable structure is fully compressed prior to withdrawal of thecatheter apparatus from the body of the subject.

Further aspects of the invention and features of specific embodiments ofthe invention are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments are illustrated in referenced figures of thedrawings. It is intended that the embodiments and figures disclosedherein are to be considered illustrative rather than restrictive.

FIG. 1 is an isolated perspective view of a device according to a firstexample embodiment, showing an expandable structure in an expandedconfiguration.

FIG. 2 is an isolated bottom plan view of the device of FIG. 1.

FIG. 3 is a front, perspective view of the device of FIG. 1, showing theexpandable structure secured to a stabilizer catheter and a deliverycatheter.

FIG. 4 is a front, perspective view of the device of FIG. 1, showing theexpandable structure secured to the stabilizer catheter and to twodelivery catheters.

FIG. 5 is an isolated front plan view of the device of FIG. 1, showingthe expandable structure in a fully compressed configuration, without aretractable catheter sheath.

FIG. 6 is an isolated front plan view of FIG. 5, showing the retractablecatheter sheath surrounding the expandable structure.

FIG. 7 is a schematic diagram illustrating the device of FIG. 4,depicting an imaginary cylinder to explain a radial limit of theexpandable structure.

FIG. 8A is an isolated front, perspective view of a device according toa second example embodiment, showing an expandable structure in anexpanded configuration secured to two sleeves.

FIG. 8B is an exploded view of FIG. 8A.

FIG. 9 is a perspective view of the device of FIG. 8A, showing theexpandable structure secured to the stabilizer catheter and theretractable catheter sheath surrounding the stabilizer catheter.

FIG. 10 is a cross-sectional view taken along line 9-9 of FIG. 9.

DETAILED DESCRIPTION

The invention provides a device for stabilizing catheters. The devicecomprises an expandable structure that is radially expandable. Thedevice may be used to stabilize catheters for the delivery ofbiocompatible materials into tissues within a human body. An example ofuse of the device is to stabilize a catheter for the delivery of anchorswithin the mycocardium of the left ventricles of the heart. The devicestabilizes the delivery catheter by radially extending the expandablestructure into an expanded configuration, allowing the expandablestructure to be in contact against surfaces surrounding the desiredimplantation location. Such contact creates a state which allows thedelivery catheter and the specific implantation location to movesimultaneously. The simultaneous movement advantageously allows forcontrolled and atraumatic delivery of the anchors and other desiredbiocompatible materials into a specific implantation location while theheart is beating.

Referring to FIGS. 1 and 2, in one embodiment the device of theinvention is a device for stabilizing catheters 10. The device 10 has anexpandable structure 12 with a proximal end 14 extending to an opposingdistal end 16 along a longitudinal axis of the stabilizer 10. In someembodiments, a radius of the distal end 16 is greater than a radius ofthe proximal end 14. The distal end 16 may be defined by a distal edge18. The distal edge 18 may have a closed curve shape. In someembodiments, the distal edge 18 has a circular or an elliptical shape.

The expandable structure 12 comprises a plurality of closed cells 20arranged radially in one or more rows between the proximal 14 and distal16 ends. In an example embodiment, the closed cells 20 are arranged in afirst row 22A and a second row 22B between the proximal 14 and distal 16ends. The first row 22A is proximate to the proximal end 14, and thesecond row 22B is proximate to the distal end 16. Each of the closedcells 20 is defined by an area, i.e., the space enclosed by each of theclosed cells 20 in the plane defined by an outer surface of theexpandable structure 12. In an example embodiment, the average area ofeach of the closed cells 20 in the first row 22A is greater than theaverage area of each of the closed cells 20 in the second row 22B.

In some embodiments, the closed cells 20 in the second row 22B each hasa diamond-shape. In such embodiments, the distal edge 18 has alternatingsets of first terminal ends 24 and second terminal ends 26. Each of thefirst 24 and second 26 terminal ends are connected by a diagonal element28. The first terminal ends 24 may be distally positioned from thesecond terminal ends 26. The average distance between the proximal end14 of the expandable structure 12 and each of the first terminal ends 24may be greater than the average distance between the proximal end 14 ofthe expandable structure 12 and each of the second terminal ends 26.

In example embodiments, an attachment member 30 is arranged to secure acatheter 32 to the expandable structure 12. The attachment member 30 mayextend distally from the distal edge 18. In an example embodiment, theattachment member 30 extends distally from one of the first terminalends 24. Referring to FIG. 3, in an example embodiment, the catheter 32comprises an elongate tubular body 36 extending longitudinally from aproximal end (not shown) to a distal end 38. The tubular body 36 may bemade of a flexible material. A distal tip 40 may be secured to andextend distally from the distal end 38 of the catheter 32. In someembodiments, the catheter 32 is a delivery catheter, such as an anchordelivery catheter. The anchor delivery catheter 32 may comprise one ormore anchors housed within the body 36. Means are provided within thecatheter 32 to advance the one or more anchors 39 to a desiredimplantation location within the body through the distal tip 40.

A connector 34 may be arranged to project from the catheter 32 to engagethe attachment member 30. The connector 34 may be positioned near thedistal tip 40 of the catheter 32. In some embodiments, the connector 34is positioned on a surface of the tubular body 36 proximate to thedistal end 38. In an example embodiment, the attachment member 30comprises a closed loop, and the connector 34 comprises a hook. The hookof the connector 34 is dimensioned to engage the corresponding closedloop of the attachment member 30. The attachment member 30 and connector34 may however be in any other suitable structural forms which allow forsecure connection between the expandable structure 12 and the catheter32.

In some embodiments, when the connector 34 is coupled to the attachmentmember 30, the distal tip 40 of the catheter 32 is positioned at a pointequal to or greater than a radial limit of the expandable structure 12.The radial limit of the expandable structure 12 is defined by a maximumradius of the expandable structure 12 when the expandable structure 12is in a fully expanded configuration. When the distal tip 40 of thecatheter 32 is positioned at a point equal to or greater than the radiallimit of the expandable structure 12, the biocompatible materials (suchas anchors) that are advanced from the distal tip 40 will be deliveredto an implantation location that is positioned at a point at or beyondthe radial limit of the expandable structure 12.

In an example embodiment, the tubular body 36 has a curved portion 37proximate to the distal end 38 of the catheter 32. A single point ofconnection between the expandable structure 12 and the catheter 32,specifically at their respective distal edge 18 and distal end 38,advantageously allows for accommodating such a catheter (i.e., acatheter with a curved portion at its distal end). A single point ofconnection also facilitates ease of coupling of the catheter to thedevice.

FIG. 7 schematically illustrates the distal tip 40 of the catheter 32being positioned at a point greater than a radial limit of theexpandable structure 12. In FIG. 7, the radial limit of the expandablestructure 12 is referred to as a circular base (R_(L)). When the distaltip 40 of the catheter 32 is at a point greater than a radial limit ofthe expandable structure 12, an angle greater than zero is createdbetween the curved portion 37 of the catheter 32 and a longitudinalsurface (S) of an imaginary cylinder extending longitudinally from thecircular base (R_(L)), parallel to the longitudinal axis of theexpandable structure 12, in a direction towards the proximal end 14 ofthe expandable structure 12.

The expandable structure 12 may be secured to a stabilizer catheter 46.The stabilizer catheter 46 may for example be a low profile catheter.The stabilizer catheter 46 may be defined by a hollow body 48. Theproximal end 14 of the expansible structure 12 may be secured to an endof the hollow body 48. The stabilizer catheter 46 may extend from thehollow body 48 at its proximal end to the expansible structure 12 at itsdistal end.

The catheter 32 is insertable through the hollow body 48 of thestabilizer catheter 46, and extends longitudinally towards theattachment member 30 to allow the connector 34 of the catheter 32 toalign and couple to the attachment member 30. In the use position, thecatheter 32 is located within a central axis of the stabilizer catheter46.

The expandable structure 12 is expandable in a radial direction. Means42 are provided to radially extend the expandable structure 12 between acompressed configuration and an expanded configuration (see FIGS. 3 and6). In some embodiments, means 42 comprises a retractable cathetersheath 44. The retractable catheter sheath 44 is moveable along thelongitudinal axis of the expandable structure 12 and/or the stabilizercatheter 46, and is dimensioned to radially surround the expandablestructure 12 and/or the stabilizer catheter 46. The expandable structure12 may be fully or partially expanded. The extent of which theexpandable structure 12 is expanded corresponds to the amount ofretraction of the retractable catheter sheath 44 towards the proximalend 14 of the expandable structure 12. For example, when the expandablestructure 12 is fully expanded, the retractable catheter sheath 44 ismoved proximally to the proximal end 14 of the expandable structure 12to be fully withdrawn from the expandable structure 12. When theexpandable structure 12 fully compressed, the retractable cathetersheath 44 is moved distally towards the distal end 16 of the expandablestructure 12 to fully surround the expandable structure 12. When theexpandable structure 12 is partially expanded, the retractable cathetersheath 44 is positioned at a point between the proximal 14 and distal 16ends. The diameter of the distal edge 18 changes as the expandablestructure 12 extends between the fully compressed configuration and thefully expanded configuration. The diameter of the distal edge 18 is at aminimum when the expandable structure 12 is in the fully compressedconfiguration (see FIGS. 5 and 6), and the diameter of the distal edge18 is at a maximum when the expandable structure 12 is in the fullyexpanded configuration.

The expandable structure 12 has a stiffness in an amount sufficient toresist displacement of the device 10 during the advancement ofbiocompatible materials (e.g., anchors) from the delivery catheter 32.The rigidity of the expandable structure 12 facilitates precisepositioning of the delivery catheter 32 to the specific implantationlocations in a moving heart. The desired stiffness of the expandablestructure 12 can be provided by varying the thickness of the materialsused and/or by modifying the configuration of the closed cells 20 (e.g.,by reducing or increasing the number of rows of closed cells 20 and/orvarying the area of one or more rows of the closed cells 20, etc.).

The expandable structure 12 is made of a biocompatible material. In someembodiments, the expandable structure 12 is made of a material thatallows for self-expansion of the structure 12 after retraction of theretractable catheter sheath 44. In some embodiments, the expandablestructure 12 is made of a shape memory alloy. An example of a suitableshape memory alloy that can be used is Nitinol.

In the fully expanded configuration, the expandable structure 12 maytaper inwardly as it extends from the proximal end 14 to the distal end16 as best shown in FIG. 3. In some embodiments, the expandablestructure 12 comprises either a tulip or cone shape in the fullyexpanded configuration.

The device 10 may optionally include a cover (not shown) mountable overthe expandable structure 12. The cover may be provided to prevent injuryto the implantation location.

The device 10 may include means for simultaneously rotating theexpandable structure 12 and the delivery catheter 32. In someembodiments, the means for rotating the expandable structure 12 and thedelivery catheter 32 further includes simultaneously rotating thestabilizer catheter 46 with the expandable structure 12 and the deliverycatheter 32.

Some embodiments of the device 10 include a plurality of attachmentmembers 30. This is best illustrated in FIG. 4. The attachment members30 each extends distally from a separate point along the distal edge 18of the expandable structure 12. The plurality of attachment members 30may be provided to each couple to a connector 34 projecting from arespective delivery catheter 32. In such embodiments, each of thedelivery catheters 32 is inserted within the hollow body 48 of thestabilizer catheter 46. The attachment members 30 may be positionedspaced-apart radially along the distal edge 18. In some embodiments, thedevice 10 includes two attachment members 30. The two attachment members30 may for example be positioned diametrically opposed from one another.The two attachment members 30 may each be provided to secure onedelivery catheter 32 to the expandable structure 12.

Referring to FIGS. 8A, 8B and 9, in some embodiments, the device 10includes one or more sleeves 52, each having a hollow body 54 throughwhich the delivery catheter 32 is insertable therein. Each of thesleeves 52 extends longitudinally from a proximal end 56 to a distal end60. When the expandable structure 12 is in a fully compressedconfiguration, the longitudinal length of each of the sleeves 52,extending from the proximal end 56 to the distal end 60, isapproximately equal to the longitudinal length of the expansiblestructure 12, extending from the proximal end 14 to the distal end 16.When the expandable structure 12 is being extended to an expandedconfiguration, its longitudinal length decreases, thereby forming acurved region 58 between the proximal end 56 and the distal end 60. Thecurved region 58 may have a concave shape, shaped to allow the distalend 60 of the sleeve 52 to contact the distal end 16 of the expandablestructure 12. The sleeves 52 may be secured to the expandable structure12. In some embodiments, the sleeves 52 are secured to the expandablestructure 12 by welding at least a portion of the sleeve 52 to theexpandable structure 12. In the example embodiments, each of the sleeves52 are secured to the expandable structure 12 by securing the proximalend 56 of each of the sleeves 52 to the proximal end 14 of theexpandable structure 12, and the distal end 60 of each of the sleeves tothe distal end 16 of the expandable structure 12. A plate 62 may bearranged at the proximal end 14 of the expandable structure 12 for theproximal ends 56 of the sleeves 52 to secure thereto. In suchembodiments, the attachment members 30 may be omitted. In otherembodiments, the expandable structure 12 includes one or more attachmentmembers 30 arranged to project from the distal end 16 of the expandablestructure 12. In such embodiments, each of the sleeves 52 includes atleast one connector 34 such a hook arranged to secure to an attachmentmember 30. Similar to the expandable structure 12, the sleeves 52 may bemade of a biocompatible material, such as Nitinol.

Referring to FIGS. 9 and 10, in some embodiments, the stabilizercatheter 46 is keyed into the retractable catheter sheath 44 so thatwhen the stabilizer catheter 46 rotates, the catheter sheath 44 isrotated also. This may improve torque response during use.

The invention provides a method of using the device 10. An examplemethod of use includes delivering a biocompatible material to a desiredimplantation location within a heart of a subject using a stabilizer.The biocompatible material may for example include anchors or pacemakerleads. Any other suitable biocompatible materials may however bedelivered by the use of the device 10 to stabilize suitable cathetersknown in the art. In an example embodiment, the device 10 is used todeliver ventricular anchors in the myocardium in the left ventricles ofthe heart.

The method may begin with the expandable structure 12 as a standalonetool. In such embodiments, the expandable structure 12 is first securedto an end of the stabilizer catheter 46. In some embodiments, thecatheter 32 may insert through the hollow body 48 of the stabilizercatheter 46 and extend distally towards the attachment member 30. Theconnector 34 of the catheter 32 aligns with and couples to theattachment member 30 to secure the catheter 32 to the expandablestructure 12. In other embodiments, the catheter 32 may insert throughthe hollow body 48 of the stabilizer catheter 46 and the hollow body 54of the sleeve 52, and extends out of the distal end 60 of the sleeve 52.In some embodiments, the expandable structure 12 is provided with thestabilizer catheter 46 and/or catheter 32 already secured in position.In such embodiments, the steps of securing the expandable structure 12to the stabilizer catheter 46 and/or the catheter 32 can be eliminated.In some embodiments, more than one catheters 32 are inserted through thehollow body 48 of the stabilizer catheter 46. In such embodiments, aplurality of attachment members 30 are provided, each positioned tocouple to a respective one of the catheters 32.

The expandable structure 12 of the device 10 is arranged in a fullycompressed configuration by positioning the retractable catheter sheath44 over the expandable structure 12 prior to advancement into a body ofa subject. In an example embodiment, the device is advanced to the leftatrium of the heart via transfemoral and/or transseptal access, acrossthe mitrel valve to reach a desired region. The desired region isproximate to the desired implantation location. In some embodiments, thedesired region is below the papillary muscle tips. In such embodiments,the desired implantation location is the myocardium.

Once the expandable structure 12 reaches the desired region, such asbelow the papillary muscle tips, the retractable catheter sheath 44 ismoved in the proximal direction of the expandable structure 12 topartially expand the expandable structure 12. Some embodiments of themethod involve rotating the partially expanded expandable structure 12and/or catheter 32 and/or stabilizer catheter 46 simultaneously toposition the catheter 32. Such positioning comprises preciselypositioning the distal tip 40 of the catheter 32 at the desiredimplantation location, such as the mycocardium. Specifically, the distalend 38 of the catheter 38 or the distal end 60 of the sleeve 52 (inembodiments in which the device 10 includes one more sleeves 52) isfirst brought into contact with the desired region. The distal tip 40 ofthe catheter 32 is then advanced from the distal end 38 of the deliverycatheter 32 or the distal end 60 of the sleeve 52 at the desiredimplantation location, such as a certain depth into the myocardium.

When the distal tip 40 of the catheter 32 is precisely positioned at theimplantation location, the retractable catheter sheath 44 is movedfurther proximally towards the proximal end 14 of the expandablestructure 12 to fully expand the expandable structure 12. In a fullyexpanded configuration, the expandable structure 12 is in contact withsurfaces within the region. In an example use embodiment, the distaledge 18 of the expandable structure 12 fills the ventricular cavitycompletely or partially when the expandable structure 12 is in a fullyexpanded configuration. The contact between the expandable structure 12and the surfaces within the region proximate to the desired implantationlocation allows the expandable structure 12 and the region to movetogether as the heart beats with normal ventricular motion. The zero netmotion between the expandable structure 12 and the region creates, fromthe frame of reference of the delivery catheter 32, a motionlessimplantation location (and vice versa from the frame of reference of theimplantation location) thereby stabilizing the catheter 32 against theimplantation location. This allows for controlled and atraumaticdelivery of biocompatible materials from the delivery catheter 32 intothe implantation location while the heart is beating.

In an example use embodiment the catheter 32 is used to deliver one ormore ventricular anchors 39 to the myocardium. The catheter 32 may bedefined by a hollow body 50 through which the anchor 39 may travel fordelivery into the myocardium. The anchor 39 may be delivered directlyinto the myocardium through the catheter 32. Alternatively the anchor 39may be advanced within a hollow needle which is embedded into themyocardium. The anchor 39 may optionally include an attached tether andguidewire dimensioned to traverse the vasculature to an external to asubject.

After the biocompatible materials are delivered to the implantationlocation, the expandable structure 12 may first be compressed in thefully compressed configuration by moving the retractable catheter sheath44 distally over the expandable structure 12. The device 10 may then bewithdrawn from the body of the subject.

The advancement of the device to the desired region and/or implantationlocation may be guided by echocardiography.

Throughout the foregoing description and the drawings, in whichcorresponding and like parts are identified by the same referencecharacters, specific details have been set forth in order to provide amore thorough understanding to persons skilled in the art. However, wellknown elements may not have been shown or described in detail or at allto avoid unnecessarily obscuring the disclosure.

As will be apparent to those skilled in the art in the light of theforegoing disclosure, many alterations and modifications are possible inthe practice of this invention without departing from the scope thereof.Accordingly, the description and drawings are to be regarded in anillustrative, rather than a restrictive, sense.

The invention claimed is:
 1. A device for stabilizing a deliverycatheter, comprising: a radially expandable structure extending from aproximal end to an opposing distal end along a longitudinal axisthereof, the distal end defining a distal edge and wherein the proximalend is secured to a stabilizer catheter; means for positioning thedelivery catheter, wherein the means for positioning the deliverycatheter comprises at least one sleeve extending from a proximal end toa distal end, wherein at least one of the proximal end and the distalend of the sleeve being fixedly secured to the expandable structure, andwherein the sleeve is arranged for the delivery catheter to beinsertable therethrough; and a retractable catheter sheath moveablealong the longitudinal axis of the expandable structure to extend theexpandable structure between a compressed configuration and an expandedconfiguration.
 2. The device according to claim 1, wherein the proximalend of the sleeve is secured to the proximal end of the expandablestructure, and the distal end of the sleeve is secured to the distal endof the expandable structure.
 3. The device according to claim 2, whereinthe sleeve is secured to the expandable structure by welding.
 4. Thedevice according to claim 1, wherein when the expandable structure is inthe expanded configuration, the sleeve further comprises a curvedregion, extending between the proximal end and the distal end, andwherein the curved region comprises a concave shape.
 5. The deviceaccording to claim 1, further comprising a plate arranged at theproximal end of the expandable structure, wherein the proximal end ofthe sleeve is secured to the plate.
 6. The device according to claim 1,wherein a radial limit of the expandable structure is equal to a maximumradius of the expandable structure when the expandable structure is in afully expanded configuration.
 7. The device according to claim 1,wherein the stabilizer catheter comprises a hollow tube with a proximalend and an opposing distal end, the expandable structure being securedto the distal end of the stabilizer catheter.
 8. The device according toclaim 1, wherein the expandable structure comprises a plurality ofclosed cells arranged radially in one or more rows.
 9. The deviceaccording to claim 1, wherein the distal end of the expandable structuretapers radially inwardly when the expandable structure is in theexpanded configuration.
 10. The device according to claim 1, wherein theat least one sleeve comprises a plurality of sleeves, each of thesleeves arranged to position one of the delivery catheters.
 11. Thedevice according to claim 10, wherein the at least one sleeve comprisestwo sleeves arranged diametrically opposed to each other.
 12. A devicefor stabilizing a delivery catheter, comprising: a radially expandablestructure extending from a proximal end to an opposing distal end alonga longitudinal axis thereof, the distal end defining a distal edge andwherein the proximal end is secured to a stabilizer catheter; means forpositioning the delivery catheter, wherein the means for positioning thedelivery catheter comprises at least one sleeve extending from aproximal end to a distal end, wherein the distal end of the sleeve issecured to the expandable structure by coupling to an attachment memberprojecting from the distal edge of the expandable structure, and whereinthe sleeve is arranged for the delivery catheter to be insertabletherethrough; and a retractable catheter sheath moveable along thelongitudinal axis of the expandable structure to extend the expandablestructure between a compressed configuration and an expandedconfiguration.